We don't particularly like to bring up D.C.'s rep as "Hollywood for ugly people" because, well, we think it's a bit rude. But on such occasions as a presidential inauguration, our town turns into what can only be called "Washington for famous people" – A-listers love our slightly more cerebral spotlight. By now, you're well aware that Beyoncé, Jay-Z, and Katy Perry are in town, and that Lady Gaga is rumored to be playing the Staff Ball tonight. But, if you're going to be out and about tonight, you'll probably see a bevy of other celebs, too. Here's the short list of stars to look for — just remember to play it cool if you spot any, okay?